1. https://protonmail.uservoice.com/forums/932839-proton-drive/suggestions/43675374-share-upload-folder-link Folder sharing is nice but it would be nicer if:

There should be these permissions for folders:

Edit - download, upload, view, edit files in the folder (like proton docs, spreadsheets);
View only - no download, no upload, only view, no edit;
Upload only - no download, no view, upload, no edit;
Upload and download - upload, view, download, no edit of the files in the folder (like proton docs, spreadsheets).

There should be these permissions for docs:

Edit - download, view, edit
View only - no download, only view, no edit;

There should be these permissions for other files not supported to edit (videos, music etc):

Edit - download, view
View only - no download, only view.

1. You could add a download permission as a slider, the same way as there is a parameter for a link duration or password. If you revoke the permission for download the file cannot be download. If you assign it, it can be download. It could be shown only when selecting edit permission. Then Upload only and Upload and download can be merged into Upload and view and Only upload and the download permission can be toggleable.

All permissions should be clearly explained with info icons next to what they grant. I didn't know that edit permission for folders lets you to upload files until I found the suggestion above and the admin's comment. For example edit permission for videos doesn't give any difference from view only.